Percolator and the like and heating element therefor



mo 22, mm, a. L. WHEGANED I lfiwfizfi PERCOLATOR AND THE LIKE ANDHEATING ELEMENT THEREFOR Filed July 2. 1928 2 Sheets-Sheet 1 PERCOLATORAND THE LIKE -AND HEATING ELEMENT THEREFOR E, 5,. 'WIEGAND Filed July 2,1 928 2 Sheets-Sheet 2 Patented Oct. 21, 1930 EDWIN In 'WIEGAND, OFPITTSBURGH, PENNSYLVANIA PERCOLATOR AND THE LIKE AND HEATING ELEMENTTHEREFOR Application filed July 2, 1928. Serial No. 289,819.

This invention relates to improvements in electrically heatedpercolators and the llke,

and it has to do more especially with an im-' proved heating element foruse in devices of 6 this class.

Among the objects of the invention are to provide an electrical heatingelement that is peculiarly adapted for use in vessels of the class abovereferred to that is extremely etficient; that is long lived that isdesigned to accomplish the most effective distribution of heat; thatgenerates the required degree of heat at the minimum current input; thatis relatively simple of construction and 1s substantial and durable, andthat is designed to expedite and cbeapen manufacture and facilitate itsincorporation in a vessel,

Heretofore, in electrically heated vesselsof the class in question, twogeneral varieties of heating elements have been employed, one, abottom-applied unit which is suitably supported below and in contactwith the bottom wall of the vessel, and the other a socalled immersiontype unit, which is so arranged as to be practically surrounded by thecontents of the vessel.

In this invention'I combine the bottomapplied and immersion type units,preferably in a self-contained element, with the following peculiaradvantages: Less time is required for initiation of the percolatingaction, which is effected by the immersed portion of the heatingelement; increased speed in the heating of the entire percolatorcontents, to which result the bottom-applied portion of the elementmaterially contributes; the division or apportioning of the total-wattage derived from socket devices between the two portions of theelement thus avoiding ovrloading or overheating and making itunnecessary to employ as highly efficient and as expensive insulationfor the bottom of the vessel as. would otherwise be necessary since onlya part of the energy input is delivered to the bottom-applied portion ofthe element; a saving in the cost of heating the entire contents of thevessel is realized, since a better distribution of the heat is elfected;5 and, for the same reason, i. e., a better distribution or difiusion ofthe heat, the life of the element is not impaired by overrating.

Other objects and advantages will appear as I proceed to describe theinvention in detail, reference being had to the accompany ing drawingswherein Fig. 1 is a sectional side elevation of a percolatorincorporating my improved heating element; and Figs. 2 and 3 arehorizontal sections on the respective lines 22 and 33 of Fig. 1, theviews being taken as though looking in the direction of the arrowsassociated with said lines.

The percolator, designated generally by the reference numeral 1, may beof standard construction excepting as to certain features devised in theapplication of the invention to the structure. An opening is made in thecenter of the bottom wall 2 of the percolator, and the same issurrounded by an annular flange 3 that is offset upwardly from the planeof said bottom wall a suitable distance; and an annular depression 4 isformed in the bottom wall a relatively short distance inwardly of itsperiphery. Suitably secured, asby welding, to the bottom wall 2outwardly beyond the depression 4 is the inwardly flanged upper end of abase shell 5 that flares outwardly at its lower end and is formed toprovide a seat'for an insulated bottom 8 that-is set upwardly within thebase and is shown as equipped with feet 9.

The heating element comprises a flat and relatively thin annular portionor unit 10, anda cylindrical portion or unit 11, that are connectedtogether by a hub 12. The por- 35 tion 10 of the element preferablyconsists of a ring unit like that constituting the subject matter of myLetters Patent No. 1,614,331, dated January 11, 1927, the samecomprising a sheath of relatively thin sheet metal. a resistor withinthe sheath that is spaced from the walls thereof, and a body ofrefractory electrical insulating heat conducting material filling thespace between the sheath and resistor. The terminals of the resistor inthe portion 10 proiect from the bottom thereof in the form of bindingposts and are designated 15.

The portion 11 of the element is preferably of the same class of heatingunits as the portion and is shown as consisting of a relatively deep cuplike sheath 16 of sheet metal that is filled with refractory electricalinsulating heat conducting material 17 3 within which is embedded aresistor 18 whose terminals 19 are extended through the bottom of theportion 11 and turned laterally and connected to the posts or terminalsof the portion 10. Also secured to the terminals or posts 15 are theinner ends of terminal pins 20 that extend through a block 21 ofinsulating material that is reduced at its outer end and set intoaflanged opening in the wall of the base shell 5. The pins 20 are soformed as to retain the block 21 in place. It is evident from what hasjust been said that the resistors of the two portions of the heatingelement are in parallel and that current supplied thereto by theapplication of a suitable fitting to the terminal pins 20 will bedivided between the two portions.

As herein disclosed, the lower end of the portion 18 of the element isclosed by an inner washer 25, which may be of suitable metal, and anouter washer 26 of mica or other approved insulating material, and that'the terminals 19 of the resistor 18 are led out through relativelylarger holes in the washer 25, and through holes of a size tocomfortably accommodate the terminals in the .washer 26. The terminalsare thus maintained out of contact with the metallic washer 25.

The cylindrical portion 11 of the element is fitted into-the bore of thehub 12 and is preferably brazed or welded thereto at the upper end ofsaid hub, as indicated at 27. The hub has a circumferential flange 28intermediate its ends that is fitted upwardly against the annularportion3 of the bottom wall 2 and occupies the recess beneath saidportion so that the bottom of the flange 28 is substantially flush withthe under surface of the bottom wall 2. 'The annular portion or ringunit 10 of the heating element is fitted over the lower end of the hub12 and is secured thereto as by peening over of the lower extremity ofthe hub. The element is clamped to the bottom wall 2 of the vessel bymeans of a nut 29 that is screwed down onto the threaded upper end ofthe hub 12 thereby to clamp the annular portion 3 of the bottom wallbetween said nut and the flange 28 of the hub; and with the element thussecured to the vessel. the portion 10 is held in close contact with thebot- .a double Walled pressure chamber 30, the

space between the walls of said chamber being air tight. The interior ofthe chamber 30 communicates with the space exterior thereof throughpassageways 32. The usual tube 35 rises from the pressure chamber 30 andsupports the coffee basket 36 in receiving relation to its upper ordischarge end.

The percolating action in the present case is the same as that in allpercolators of the valveless type and therefore it is deemed unnecessaryto describe the same. It will be noted, however, that by reason of theintimate contact of the liquid within the chamber 30 with the portion 11of the element, that said liquid will be very quickly raised to thepercolating point; and at the same time the contents of the percolatoroutside the chamber 30 will be deriving heat from the portion 10 of theelement, which will materially hasten the heating of the entire contentsof the vessel. I

By this means I utilize, with safety to the heating elements, themaximum rate of energy input available from the customary socket outlet.

Having thus described my invention, what I claim is:

1. In combination, a vessel of the class set forth whose bottom wall isprovided with an opening, and an electrical heating element comprising aheat generating portion that is applied to the underside of the bottomwall about said opening, a second heat generating portion that riseswithin the vessel through said opening, a hub connecting said portionstogether, and a member applied to the hub above the bottom wall forholding the first mentioned portion of the heating element against theunderside of said wall.

2. In combination, a vessel of the class set forth whose bottom wall isprovided with an opening, and an electrical heating element comprisingaheat generating portion that is applied to the underside of the bottomwall about said opening, a second heat generating portion that riseswithin the vessel through said opening, a hub connecting said portionstogether and having an externally threaded part extending above saidbottom wall, and a nut applied to the threaded part of the hub forholding the first mentioned portion of the heating element against theunderside of said wall.

3. In combination, a vessel of the class set forth whose bottom wall isprovided with an opening, the portion of said bottom wall immediatelysurrounding said opening being offset upwardly from the plane of theremaining portion thereof so as to provide a downwardly facing recess,and an electrical heating element comprising a heat generating portionapplied to the underside of the hotwardly facing recess, and anelectrical heating element comprising a heat generating portion appliedto the underside of the bottom wall about said opening, a second heatgenerating portion that rises within the vessel through said opening,a-hub connecting said portions together and involving a circumferentialflange fitting within the aforesaid recess, and a member applied to thehub above the bottom wall for clamping the portion of said wall adjacentthe opening between itself and the flange of the hub.

5. In combination, a vessel of the class set forth whose bottom wall isprovided with a substantially central opening, the portion of saidbottom wall immediately surrounding said opening being offset upwardlyfrom the plane of the remaining portion thereof so as to provide adownwardly facing recess, and an electrical heating element comprising aheat generating portion'that is applied to the underside of the bottomwall about said opening, a second heat generating portion that riseswithin the vessel through said opening, a hub connecting said portionstogether and involving a circumferential flange fitting 'within theaforesaid recess, the hub having a part extending above said flange andbeing externally threaded, and a nut for application to the threadedpart of the hub for clamping between itself and said flange the portionof the bottom wall surrounding said opening.

6. In combination, a vessel of the class set forth whose bottom wall isprovided with a central opening, the material of said wall about saidopening being offset upwardly from the plane of the remaining portion ofsaid wall thereby to provide a downwardly opening recess, an electricalheating element comprising an annular unit for application to theunderside of the bottom wall, a hub having a circumferential flangeintermediate its ends, the portion of said hub below said flangeextending through the opening in said annular unit and secured to theunit, the part of the hub above said flange being externally threaded, anut applied to the threaded part of the hub for clamping between itselfand the aforesaid flange the material of the bottom wall surroundingsaid opening, and a cylindrical heating unit risin within the vessel andhaving its lower e1, secured within the hub.

7. A percolator comprising a vessel having an opening in its bottomwall, an electrical heating element having a heat generating portionapplied directly to the underside of the bottom wall and a second heatgenerating portion rising through said opening, a member applied to theelement above said bottom wall for clamping the element to said wall, apressure chamber surmounting said member and enclosing the secondportion of the heating element, a tube rising from said chamber, and abasket supported in receiving relation to the discharge mouth of saidtube.

In testimony whereof, I hereunto afl'ix my signature.

1 EDWIN L. WIEGAND.

